On the other hand, Mendeleyev’s periodic table of the elements was organised according to the atomic masses, implying that the mass was responsible for atoms’ structure and chemical behaviour. The model suggested that the charge on the nucleus was the essential characteristic of the atom, determining its structure. However, the Rutherford atomic model was not readily accepted by all physicists, as it did not conform to the then chemical understanding of the atom. Most alpha particles went directly through the foil, but some were diverted by the foil and hit the spot on a screen placed off to one side. Remembering those results, Rutherford had his postdoctoral fellow, Hans Geiger, and an undergraduate student, Ernest Marsden, refined the experiment by beaming alpha particles through gold foil and recognised them as beams of light or scintillations on a screen. For some particles, the blurring resembled a two-degree deflection. In contrast, alpha particles transmitted through a sheet of mica only 20 micrometres thick would create an effect with blurry edges. Five years earlier, Rutherford observed that alpha particles transmitted through a hole onto a graphic plate would make a sharp-edged picture. He named these circular paths orbits.īy improving on Thomson’s model of the atom Rutherford in 1911 depicted that the atom has a dense nucleus with the help of the gold-foil experiment, and thereby improved the understanding of the atomic model. Rutherford also proposed that the electrons move at the speed of light around the nucleus. Rutherford’s nuclear model also proposed that the negatively charged electrons encircle the nucleus of an atom.

He called this region of the atoms a nucleus.

It describes the atomic model as to where all the atom’s mass is concentrated in the centre called the nucleus, around which the negative charges called the electrons revolve.Īccording to Rutherford’s atomic model, the positively charged particles and most of the atom’s mass was concentrated in a minimal volume. The Rutherford atomic theory has defined the atom as a tiny, dense, positively charged core called a nucleus, which is surrounded by negative charges called electrons. Ernest Rutherford was a New Zealand born physicist who in 1911 described the structure of an atom, which was an improvement on the plum in pudding model of atom Rutherford model is also known as the Rutherford atomic model, planetary model of the atom, or the nuclear model of the atom.

Rutherford atomic theory date